Less bias in the sense that they can answer these kinds of questions well. I'm uncertain how well rationality in these cases correlates with what we really care about, but it is clearly not super great.

These questions test for your ability to think carefully and apply knowledge of specific biases in a situation where you're prompted to "think rationally" and are being scored for not falling for tricks. If you're stuck asking survey questions, I'd ask much more personal questions like "how smart/rational are you compared to the LW distribution" (though there are problems here too).

I've met quite a few people through LW, and some were impressively rational in a very applied-to-real-life fashion. However, there's another group of about similar size that are terribly irrational when it comes to real life - engaging in motivated cognition and blind to that fact because of motivated cognition. Yet these people would probably ace this test, since they're quite good at not being explicitly and obviously wrong (they're good at looking smart). I'd guess this is more of a strength of identity effect than a "effective in real life" effect.